Episode 109

This week we look at security updates for containerd, Ruby, the Linux
kernel, Pygments and more, plus we cover some open positions within the
team as well.

Overview

This week we look at security updates for containerd, Ruby, the Linux
kernel, Pygments and more, plus we cover some open positions within the
team as well.

This week in Ubuntu Security Updates

28 unique CVEs addressed

[USN-4881-1] containerd vulnerability [00:38]

1 CVEs addressed in Focal (20.04 LTS), Groovy (20.10)

CVE-2021-21334

When using the containerd CRI implementation (kubernetes container
runtime interface) - would share environment variables etc between
containers that shared the same image - so could allow an inadvertent
info leak from one container to another - race condition so would be less
likely to occur if not launching containers in rapid succession which
share the same image

[USN-4882-1] Ruby vulnerabilities [01:27]

3 CVEs addressed in Xenial (16.04 LTS), Bionic (18.04 LTS), Focal (20.04 LTS), Groovy (20.10)

CVE-2020-25613
CVE-2020-10933
CVE-2020-10663

Crafted JSON could result in RCE - could create a malicious object within
the interpreter
Possible info leak via unintialised memory across socket operations -
heap info leak so could expose sensitive data from the interpreter
Failure to validate xfer encoding header - could bypass reverse proxy and
so be vulnerable to HTTP request smuggling attacks

[USN-4883-1] Linux kernel vulnerabilities [02:32]

3 CVEs addressed in Trusty ESM (14.04 ESM), Xenial (16.04 LTS), Bionic (18.04 LTS)

CVE-2021-27364
CVE-2021-27363
CVE-2021-27365

4.15 kernel for bionic + 4.4 kernel for xenial
3 iSCSI issues, most important was heap overflow that could be exploited
by a local attacker -> code-exec as root

Other 2 are info leak via kernel pointers being disclosed to userspace
and a OOB read -> crash or possible infoleak

[USN-4884-1] Linux kernel (OEM) vulnerabilities [03:13]

3 CVEs addressed in Focal (20.04 LTS)

CVE-2021-3348
CVE-2021-3347
CVE-2021-20194

OEM kernel - 5.10

UAF in network block device driver - local attacker could exploit for
crash/codexec

[USN-4885-1] Pygments vulnerability [03:36]

1 CVEs addressed in Xenial (16.04 LTS), Bionic (18.04 LTS), Focal (20.04 LTS), Groovy (20.10)

CVE-2021-20270

infinite loop -> CPU based DoS when parsing crafted Standard ML files -
input file containing just ’exception’ would be enough to trigger this

[USN-4886-1] Privoxy vulnerabilities [04:18]

14 CVEs addressed in Trusty ESM (14.04 ESM), Xenial (16.04 LTS), Bionic (18.04 LTS), Focal (20.04 LTS), Groovy (20.10)

CVE-2021-20214
CVE-2021-20211
CVE-2021-20276
CVE-2021-20212
CVE-2021-20275
CVE-2021-20273
CVE-2021-20272
CVE-2021-20217
CVE-2021-20216
CVE-2021-20215
CVE-2021-20213
CVE-2021-20210
CVE-2021-20209
CVE-2020-35502

Privacy enhancing HTTP proxy
Incorrect handling of:

CGI requests -> DoS/info-leak
regexes -> DoS (crash + mem-leak)
client tags -> DoS (memory leaks)

[USN-4887-1] Linux kernel vulnerabilities [05:03]

6 CVEs addressed in Bionic (18.04 LTS), Focal (20.04 LTS), Groovy (20.10)

CVE-2021-27364
CVE-2021-27363
CVE-2020-27170
CVE-2020-27171
CVE-2021-27365
CVE-2021-3444

BPF verifier failed to properly handle mod32 destination register
truncation when source register was known to be 0 -> could be turned into
an arbitrary memory read -> info-leak - and can’t rule out arbitrary
memory write -> RCE
Spectre mitigations for BPF were found to be insufficient - could allow
an attacker to read entirety of kernel memory via speculative execution
attack through BPF
iSCSI issues discussed earlier too

Goings on in Ubuntu Security Community
Hiring [07:04]
AppArmor Security Engineer

https://canonical.com/careers/2114847/apparmor-security-engineer-remote

Ubuntu Security Engineer

https://canonical.com/careers/2612092/ubuntu-security-engineer-remote

Security Engineer - Ubuntu

https://canonical.com/careers/2925180/security-engineer-ubuntu-remote

Get in contact

[email protected]
#ubuntu-security on the Libera.Chat IRC network
ubuntu-hardened mailing list
Security section on discourse.ubuntu.com
@ubuntu_sec on twitter